Ladder strip crimper



Dec. 31, 1963 G. H. SCHWALM 3,115,695

LADDER STRIP CRIMPER Filed Aug 18, 1959 8 Sheets-Sheet 1 INVENTOR. G/enclon (K Schwa/m M WiW Dec. 31, 1963 G. H. SCHWALM LADDER STRIP CRIMPER 8 Sheets-Sheet 2 INVENTOR. G/enc/on ficha/a/m Filed Aug. 18, 1959 G. H. SCHWALM LADDER STRIP CRIMPER Dec. 31, 1963 Filed Aug. 18, 1959 8 Sheets-Sheet 3 4;, 'z s z y en on Q Ma m M W W Dec. 31, 1963 e. H. SCHWALM 3,115,695

LADDER STRIP CRIMPER Filed Aug. 18, 1959 8 Sheets-Sheet 4 a WIOZ.

INVENTOR. G/endon f/ Schaua/m MWW- Dec. 31, 1963 G. H. SCHWALM .7 3,

7 LADDER STRIP CRIMPER Filed Aug. 18, 1959 a Sheets-Sheet 5 73 6O 5 HI INVENTOR. Glendon M fichu/a/m Dec. 31, 1963 G. H. SCHWALM 3,115,695

LADDER STRIP CRIMPER Filed Aug. 18, 1959 8 Sheets-Sheet 6 I INVENTOR.

Glendon Schwa/m BY Dec. 31, 1963 H. SCHWALM LADDER STRIP CRIMPER v 8 Sheets-Sheet 7 Filed Aug. 18, 1959 INVFNTOR. GLNDON H. SCHWHLM Dec. 31, 1963 G. H. SCHWALM LADDER STRIP CRIMPER Filed Aug. 18, 1959 8 Sheets-Sheet 8 INVENTOR. Guzman: H. Scnwam United States Patent 3,115,695 LADDER STEEL CREF. Glendon H. Schwaim, Harrisburg, Pa, assignor to Incorporated, Harrisburg, Pa. Filed Aug. 18, 1959, Ser. No. 834,438 6 Claims. (ill. 2933) This invention relates to insulation stripping devices for stripping the ends of electrical conductors.

An object of the invention is to provide an improved wire stripping device which is particularly adapted for use with a terminal crimping press. A further object is to provide a wire stripping device adapated for use with a terminal crimping press and having a pair of wire gripping jaws which are adapted to open and thereby to release the wire prior to the end of the operating cycle of the press.

These and other objects are achieved in a preferred embodiment comprising a pair of closable insulation-cutting knives, and a pair of pivoted Wire gripping jaws which are normally biased to their opened position. These jaws are closed by means of a cam or wedge and are mounted on a reciprocable slide member by means of which they may be retracted from the insulation-cutting knives to remove a severed section of insulation from the wire end. Movement of the slide is affected by means of pneumatic piston cylinder which engages the slide member and retracts it from the knives. Advantageously, the entire stripping mechanism, excepting the insulationcutting knives, is mounted on a pivoted platform adjacent a crimping press in a man or such that after the stripping operation has been completed, the platform is lowered so that the stripped wire is positioned within an uncrimped terminal. The cam or wedge which closes the jaws is disengaged from these jaws after movement of the pivoted platform so that the grip of the jaws on the wire is released prior to the crimping operation.

In the drawing:

FIGURE 1 is a perspective view showing a preferred embodiment of a wire stripper in accordance with the invention and showing portions of a terminal crimping press on which the wire stripper is mounted;

FIGURE 2 is a top plan view of the embodiment of FIGURE 1 with the wire gripping jaws open;

FIGURE 3 is a view similar to FIGURE 2 but showing the positions of the parts when the jaws are closed;

FIGURE 4 is a side view of the preferred embodiment;

FIGURES 5 and 6 are views similar to FIGURE 4 but showing the positions of the parts at different stages in the wire stripping cycle;

FIGURE 7 .is a view taken along the lines 77 of FIGURE 2;

FIGURE 8 is a view taken along the lines 3% of FIGURE 6;

FIGURES 9 and 10 are a side and plan view of an alternative embodiment.

FIGURE 11 is a perspective view of a terminal crimping press equipped with an applicator in accordance with the embodiment of FIGURES 9 and 10.

FIGURES 11A, 11B, and 110 are fragmentary perspective views illustrating the manner in which the insulation is stripped from the end of a wire and the stripped end is positioned in an uncrimped terminal.

The embodiment of FIGURE 1 is shown as being mounted on a terminal crimping press of the general type described of the copending application of Robert L. Albright, Serial No. 792,098, filed February 9,1959 for Lead Making Machine now Patent Number 3,046,6 3 6. Referring first to FIGURE 1, a terminal crimping press of the type described in the Albright application comprises a generally C-shaped frame member 2 having a reciprocable "ice ram 4 on which is mounted a movable or upper crimping die 6 which, during the crimping operation is moved towards and away from a lower crimping die or anvil 8. Terminals T in the form of ladder strip in which the terminals constitute the rungs of the ladder are fed automatically across a plat form it) which is pivotally mounted at one of its ends as shown at 12 and which extends through the operating zone of the press to a fixed shear block 14 and past a fixed wire support 16 which supports the electrical conductor during the final stages of the crimping operation. The shear block and support are mounted on a. plate 18 which in turn is supported upon blocks 26), these blocks being secured to the front of the C-shaped frame member 2. In the aforementioned Albright application it is pointed out that where ladder stripped terminals are being continuously fed to a crimping applicator it is desirable to sever the terminals from the carrier or side strips at the time of crimping rather than before crimping and the Albright type of terminal applicator is particularly intended to achieve this result. However, for purposes of the present invention, it is unnecessary to describe the structure of this terminal applicator in detail since it is not essential to an understanding of the present invention. It is sufficient to say that the instant invention is addressed to the problem of stripping the inserted electrical conductor at substantially the same time as the wire is cr-imped and to this end there is provided on the Albright type applicator an insulation stripping mechanism as described below.

A fixed insulation cutting blade 22 and a movable blade 24 are mounted in supporting and guiding means 26 which in turn are secured to a block 2% on plate 13. Movable blade 24 is secured at its end to a link 30 which is pivoted to the end of an arm 32 extending from a hub 34. This hub is pivotally mounted between arms 36 extending from block 2 8 and has a second arm 38 which is pivotally connected at its end to the piston rod 40 of a piston-cylinder 42. Upon downward movement of this piston rod, movable blade 24 moves towards fixed blade 22 to circumferentially cut the insulation of an insulated conductor inserted past these blades. It will be noted that these blades are positioned behind the crimping dies as viewed in FIGURE 1 and that the remainder of the insulation stripping device is mounted in front of the dies so that the wire can be inserted past the dies into the space between the cutting blades.

The mechanism for gripping and pulling the insulated conductor is mounted on a bracket 44'- having a hub portion 4 6 which is pivotally mounted on a pin extending between upstanding arms 48 which project iirom a plate 50. This plate in turn is supported on the top surface of one of the blocks 20. A spring (not specifically shown) is positioned beneath bracket 44 and normally biases this bracket upwardly to the position shown in FIGURE 1. Secured to bracket '44 is a depending portion 52 from which a support plate 54 projects laterally, and a back plate 56. A slide 58 bears against the surface of depending portion 52 and is reciprocable between gibs so. At its forward end (its end nearest to the terminal applicator) a support plate 62 is secured to this slide for reciprocation therewith and a air of levers 64 are mounted on parallel axes 63 on the top surface of this support. These levers extend inwardly and generally upwardly as viewed in FIGURE 1 toward the applicator press and have jaws 66 on their ends which are normally positioned adjacent the insulation cutting knives 22, 24. The opposite ends of these lovers are resiliently biased towards each other by means of a spring 70' and are provided with cam [followers 74 which bear against a wedge shaped cam 72. This cam is on the end of an arm 76 pivoted at its lower end between brackets 7 8 which extend from support plate 62. A spring 8b is secured to arm '76 intermediate its ends and has its opposite end secured to a pin on a bracket 82 which in turn is secured to slide member 53. This spring biases arm 76 in a clockwise direction as viewed in FIGURE 1 and tends to urge the wedge shaped cam member 72 to enter between the rollers '74 and close the wire gripping jaws.

A pneumatic piston cylinder at secured to a block 8 WllCh is secured to plate 54 has a piston rod which extends toward arm 76. The end of this rod provides a yoke hi which is notched for the accommodation of a pin 92 in arm 76. When this piston rod is extended as in FIGURES l and 2, arm 76 is held upright against the force of spring 8% and cam '72 is held out of engagement with cam followers or rollers 74 so that the jaws remain open under the influence of spring 73. Intermediate its ends piston rod 88 extends through a notch in L-shaped bracket 4 which is secured to slide member 58 so that the slide member is retracted during retraction of the piston rod. Normally the yoke on the end of the piston rod is spaced from the L-shaped bracket 94 so that there is a lost motion connection between the bracket and the yoke.

In order accurately to control rearward movement of the slide member during the stripping operation, there is provided an adjustable stop in the form. of a screw 93 which extends through plate 55. This screw bears against the rearward face of bracket 82 when the slide is in its retracted position to permit accurate positioning of the stripped end of the Wire as is described below. lso provided on plate 55 is a switch res having a switch button which is engaged by bracket 32 upon rearward movement of the slide and bracke As previously mentioned, the entire assembly is lowered during descent of the ram to position the stripped wire end in an uncrimped terminal on the lower crimping die. Such lowering of the stripping mechanism is achieved by means of a depressor rod 1% carried by the ram which engages, during descent of the ram, an car 104 of plate 44. Bar 164 extends over plate in so that the depressor rod lowers both plate 44 and plate ill during descent of the ram.

The operation of the device is as hollows assuming the parts are in the position of FIGURE 1. The operator first inserts an unstripped wire past stripping jaws 66 and between the insulation cutting knives until a microswitch in block .28 is energized. This microswitch opens a control valve (not specifically shown) which governs the admission of air into piston cylinder 4-2 to cause closure of the insulation-cutting blades and admission of air into the forward end of double-acting piston cylinder 86 to cause rearward movement of piston rod Insulation adjacent the end of the wire is circumferentially cut and immediately thereafter piston rod 8-8 is retracted so that cam 74-, under the influence of spring Ell, cams the rearward ends of the levers 64 apart thereby closing the gripping jaws. Upon further rearward or inward movement of the piston rod, yoke 99 engages. bracket 9rd and slide -8 is retracted so that the jaws move away from the insulation-cutting knives and strip the end of the wire and position the stripped end over the uncrimped terminal on the lower crimping die. When such rearward movement of the slide is completed, microswitch 1% is energised and this microswitch initiates the cy le of the crimping press. The ram then moves downwardly and prior to bottoming of the ram depressor rod 162 engages extension N34 to pivot or lower the entire stripper mechanism. Upon such movement of the platform M4 the stripped wire is positioned within the upstanding sidewalls of the terminal and the ram shortly thereafter reaches its bottom dead center position to curl these upstanding sidewalls inwardly and crimp the terminal onto the wire. FIGURES 11A, MB, and 11C illustrate the manner in which the jaws as grasp the wire, pull it from between the closed insulation cutting blades 22., 2.4, and then move rearwardly and downwardly to position the 4 stripped end in the ferrule portion of an uncrimped terminal T.

Advantageously, the jaws should release their grip on the stripped wire slightly before the crimp is 1. .de in order that the strands of the wire will be free to move slightly as the terminal is crimped. In the preferred embodiment, this action is achieved by means of a control switch actuated by the ram or some other element of the press immediately before the crimping die bottoms. This switch is not shown but it will be understood that such a switch can be provided at any convenient location, for example, it can be energized by means of a cam on the crank shaft of the press if the crimping press is of the pneumatic type or it can be energized by the piston rod of the press it the press is of the pneumatic type. in either event, the closure of such a switch reverses the valve controlling the admission of air to piston cylinder 86 and admits air to the rearward or righthand end of this piston cylinder as viewed in FIGURE 1 to cause movement of the piston rod leftwardly. Upon such movement of the piston rod, arm 76 is disengage from the cam followers '74 on the ends of levers when the jaws open. it will be apparent however, that since this opening of the jaws takes place when the ram is at bottom dead center, the slide member can not be moved leftwardly until the ram ascends. Accordingly there is provided on the face of plate as, a roller 1% which bears against an L-shaped bracket liii on block Zll. When the parts are in the position of FEGURE 6, the piston cylinder 86 tends to move slide 58 leitwardly but roller 1% prevents such leftward movement until the ram ascends at which time this roller moves over the L-shaped braclre and the parts return to their starting positions.

In an alternative embodiment of the invention shown in FIGURES 9 and 10, cylinder 86' which corresponds to the cylinder 86 of the previous embodiment is positioned beneath plate 5% and is linked to slide member 558' by means of a lever $.16 pivotally mounted intermediate its ends. A second cylinder 112 is provided in this embodiment which is mounted by means or" a plate its on slide member 5'3. t will be apparent that this embodiment substitutes a pneumatic piston cylinder for spring Si in the embodiment of FIGURE 1, and for this reason permits a somewhat tighter grip upon the insulated wire. It will also be noted that in this embodiment the micro switch 164) is located on the outside surface of plate 52 and closed by means of a pin which extends from the slide through a slot in the plate.

The operation of the embodiment of FIGURES 9 and 10 is substantially the same as the embodiment of PEG- URE 1. It will be appreciated that cylinder 112 should be actuated slightly before cylinder 36 in order that the wire will be gripped before the slide begins to retract.

FIGURE 11 shows the general appearance of one common type of crimping press when equipped with the terminal applicator of the instant invention. This particular type of press has a continuously rotating flywheel in the press housing which is coupled to the press ram through a shaft and clutch as described in the above mentioned Albright application. The terminal feed finger 122 for this type of press may be actuated by a hydraulic piston as indicated at 124.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is oliered by way of illustration only. Th actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. Insulation stripping mechanism for use with a crimping apparatus comprisins a pair of reciprocable terminal crimping dies and ram means for moving said dies relatively towards and away from each other, said mechanism comprising, a platform disposed adjacent said dies and movable in the direction of movement of said dies, a slide member on said platform movable towards and away from said dies, a pair of pivoted fingers on said slide extending towards said dies and having normally open wire gripping jaws on their ends, a pair of cooperatively aligned insulation cutting knives adjacent said dies on the opposite side thereof from said platform, means for closing said knives and said jaws and for shortly thereafter moving said slide relatively away from said dies whereby, a wire inserted past said jaws, said dies, and said knives has the insulation adjacent its end cut and removed, and the stripped end of said wire is disposed between said dies, and means on said rain for engaging said platform and moving said platform relatively towards one of said dies thereby to move said stripped end towards one of said dies and to position said stripped end in an uncrimped terminal prior to closure of said dies and crimping of said terminal.

2. Insulation stripping mechanism for use with a crimping apparatus of the type having a pair of relatively reciprocable dies and ram means for moving said dies relatively towards and away from each other, said mechanism comprising, a platform disposed adjacent said dies and movable in the direction of movement of said dies, a slide member on said platform movable towards and away from said dies, a pair of cooperatively aligned insulation cutting knives adjacent said dies and on the opposite side thereof from said platform, a pair of fingers pivoted intermediate their ends to said slide and having wire gripping jaws on one end thereof, said jaws being normally open and being normally disposed between said dies, a lever pivoted to said slide and having means on its end for engaging the opposite ends of said fingers to close said jaws, spring means engaging said lever and normally urging said lever into engagement with said jaws, piston cylinder means acting between said platform and said slide and engaging said lever in its extended position to hold said lever away from said opposite ends, said piston cylinder means having a lost motion connection with said slide whereby upon retraction of said piston cylinder, said lever engages and closes said jaws and said slide is thereafter retracted, said ram means including means for engaging said platform and moving said platform relatively towards one of said dies whereby a wire inserted past said jaws, said dies, and said knives has insulation cut and removed from its end upon movement of said knives and jaws, and the stripped end of said wire is positioned in a terminal between said dies upon movement of said platform.

3. Apparatus as set forth in claim 2 including means actuated by said slide upon retraction thereof for actuating said cram whereby said ram cycles only after stripping of said wire.

4. Apparatus for applying terminals to rthe ends of electrical conductors comprising, a pair of crimping dies movable relatively toward-s and away from each other, a platform disposed adjacent said dies on one side thereof, a pair of insulation stripping knives on the opposite side of said dies, insulation stripping means on said platform including a pair of wire gripping jaws normally extending between said dies, means on said platform to close and retnact said jaws after closure of said knives thereby to strip insulation from the end of a wire inserted between said dies, and means movable with one of said dies for engaging said platform and moving said platform towards the other of said dies thereby to position the end of said wire in an uncrimped connector disposed between said dies.

5. A device for applying electrical connectors to insulated wires comprising, a pair of crimping dies, means including a reciprocable ram for moving said dies relatively towards and away from each other, a pair of cooperatively aligned insulation cutting knives disposed in axial alignment with sm'd dies on one side thereof, a pair of wire gripping jaws adjacent said dies on the opposite side thereof, closing and moving means for closing said jaws and moving said jaws axially away from said dies, a platform disposed adjacent said die block and mounted for movement substantially normally of the axis thereof, said closing and moving means being mounted on said platform, and means on said ram for engaging said platform and moving said platform thereby to position the stripped end of a wire between said dies.

6. Apparatus for applying terminals to the ends of electrical conductors comprising, a pair of crimping dies, ram means for moving said dies relatively towards and away from each other, a platform adjacent said dies on one side thereof, engaging means on said ram for engaging said platform and moving said platform relatively towards one of said dies during movement of said ram, a pair of normally open wire gripping jaws on said platform normally disposed between said dies, a first piston cylinder means on said platform for closing said jaws and moving said jaws away from said dies, a pair of normally open insulation cutting knives adjacent said dies on the opposite side thereof from said platform, a second pneumatic piston-cylinder means for closing said knives, switch means for actuating said second pistoncylinder means upon positioning of a wire in said apparatus with its axis extending past said jaws, past said dies, and past knives, switch means for actuating said first piston cylinder means to close said jaws and strip said wire, and means responsive to said first piston cylinder for actuating said ram after stripping said wire whereby said wires is positioned in a terminal prior to closure of said dies.

References Cited in the file of this patent UNITED STATES PATENTS 1,975,005 Kingsbury Sept. 25, 1934 2,429,938 Mansfield Oct. 28, 1947 2,706,847 Jennings Apr. 26, 1955 2,765,685 Stratham Oct. 9, 1956 2,774,130 Folkenroth Dec. 18, 1956 2,859,290 Grinage Nov. 4, 1958 FOREIGN PATENTS 609,834 Great Britain Oct. 7, 1948 

1. INSULATION STRIPPING MECHANISM FOR USE WITH A CRIMPING APPARATUS COMPRISING A PAIR OF RECIPROCABLE TERMINAL CRIMPING DIES AND RAM MEANS FOR MOVING SAID DIES RELATIVELY TOWARDS AND AWAY FROM EACH OTHER, SAID MECHANISM COMPRISING, A PLATFORM DISPOSED ADJACENT SAID DIES AND MOVABLE IN THE DIRECTION OF MOVEMENT OF SAID DIES, A SLIDE MEMBER ON SAID PLATFORM MOVABLE TOWARDS AND AWAY FROM SAID DIES, A PAIR OF PIVOTED FINGERS ON SAID SLIDE EXTENDING TOWARDS SAID DIES AND HAVING NORMALLY OPEN WIRE GRIPPING JAWS ON THEIR ENDS, A PAIR OF COOPERATIVELY ALIGNED INSULATION CUTTING KNIVES ADJACENT SAID DIES ON THE OPPOSITE SIDE THEREOF FROM SAID PLATFORM, MEANS FOR CLOSING SAID KNIVES AND SAID JAWS AND FOR SHORTLY THEREAFTER MOVING SAID SLIDE RELATIVELY AWAY FROM SAID DIES WHEREBY, A WIRE INSERTED PAST SAID JAWS, SAID DIES, AND SAID KNIVES HAS THE INSULATION ADJACENT ITS END CUT AND REMOVED, AND THE STRIPPED END OF SAID WIRE IS DISPOSED BETWEEN SAID DIES, AND MEANS ON SAID RAM FOR ENGAGING SAID PLATFORM AND MOVING SAID PLATFORM RELATIVELY TOWARDS ONE OF SAID DIES THEREBY TO MOVE SAID STRIPPED END TOWARDS ONE OF SAID DIES AND TO POSITION SAID STRIPPED END IN AN UNCRIMPED TERMINAL PRIOR TO CLOSURE OF SAID DIES AND CRIMPING OF SAID TERMINAL. 